1. Field of the Invention
The invention relates to a wiring harness and a relay harness.
2. Description of the Related Art
Japanese Unexamined Patent Publication No. 2003-263930 discloses a wiring harness that uses non-halogen flame-retardant resin as a coating material that surrounds wires. This coating material ensures that the wiring harness coating does not define a spreading path for combustion during a vehicle fire.
All members of a wiring harness preferably are coated with flame-retardant resin to prevent the spread of fire in the event of a vehicle fire. However, non-halogen flame-retardant resin is more expensive than the PCV resin that is used widely as general-purpose coating. In addition, the length of wiring harnesses in an automotive vehicle and the number of wires of the wiring harness have increased in recent years. Thus, costs increase if members of the wiring harness are coated with flame-retardant resin.
Consideration has been given to applying flame-retardant coatings only to areas of the wiring harness near a device with a possibility of a fire. Thus, the spread of fire along the coating members can be suppressed to a minimum. This approach requires a structure to set only a part of the wiring area as the flame-retardant area. For example, wires in an easily flammable area use a coating with a lower flash point than wires in the flame-retardant area, and these wires are fixed, such as by crimping a sleeve-type connection terminal. The connected part then is taped to be insulated from other wires. However, a process of connecting the wires in the flame-retardant area and those in the easily flammable area using the connection terminal and the tape is performed manually by an operator, and a burden on the operator is large when the number of the wires of the wiring harness is large.
The invention was completed based on the above situation and aims to reduce a burden on an operator in the manufacturing of a wiring harness in which a part of a wiring area is a flame-retardant area.